1. Field of the Invention
The present invention relates to a welding wire tangling-prevention device for a welding wire received in a large-capacity pail pack in the form of a tube-shaped wound body including eccentrically-stacked continuous spiral loops. More particularly, the present invention relates to a welding wire tangling-prevention device for a welding wire received in a large-capacity pail pack in the form of a tube-shaped wound body including eccentrically-stacked continuous spiral loops, provided with means for controlling the welding wire to be freely drawn out between alternating comb teeth while preventing subsequent loops of the welding wire from being lifted and tangled.
2. Background Art
In order to prevent tangling of a welding wire received in a large-capacity pail pack in the form of a tube-shaped wound body including eccentrically-stacked continuous spiral loops, various drawing devices have been proposed. These drawing devices use an annular member laid on the top of the tube-shaped wound body to allow the welding wire to be drawn out via the inside or outside of the annular member.
Examples of the drawing device adapted to draw out the welding wire via the inside of the annular member are disclosed in Korean Patent Publication No. 87-1076, Japanese Patent Laid-Open Publication No. Sho. 61-183057 and Japanese Patent Laid-Open Publication No. Hei. 11-192552. When an uppermost loop of the welding wire is drawn out while being loosened, a subsequent loop of the welding wire may be gradually increased in diameter due to the elasticity of the welding wire, so that it protrudes between the outer surface of the drawing device and the inner surface of the pail pack.
Korean Patent Publication No. 87-1076 discloses an annular member having buffering wings for preventing the welding wire from protruding between the outer surface of the annular member and the inner surface of the pail pack while allowing the welding wire to be freely lowered along the inner surface of the pail pack as the welding wire is consumed. Japanese Patent Laid-open Publication No. Sho. 61-183057 discloses a vertical strip attached to the inner surface of the pail pack to prevent the welding wire from protruding between the outer surface of the annular member and the inner surface of the pail pack while allowing the welding wire to be freely lowered along the strip. As the welding wire is freely lowered along the strip, no space is formed between the top of the wound body and the annular member, so that it is possible to prevent tangling of the welding wire. In particular, Japanese Patent Laid-open Publication No. Sho. 61-183057 takes into consideration the tendency of the welding wire to be lifted via the outside of the annular member, which thereby causes tangling of the welding wire. However, the conventional drawing devices configured to draw out the welding wire via the inside of the annular member frequently involve the problem that when the uppermost loop of the welding wire is drawn out, subsequent loops of the welding wire are drawn out by the uppermost loop, so that the welding wire becomes tangled. In order to solve this problem, Korean Utility Model Publication No. 91-5819 and Japanese Patent Publication No. Hei. 4-133973 have proposed use of a weight adapted to be laid on the annular member because the above-mentioned problem was considered to be caused by an insufficient weight of the annular member. However, it is impossible for this technique to effectively control the subsequent loops of the welding wire drawn out by the uppermost loop of the welding wire.
In particular, Japanese Patent Laid-open Publication No. Hei. 11-192552 discloses a proposal in which the annular member has a reduced drawing hole so as to control the subsequent loops of the welding wire drawn out by the uppermost loop of the welding wire. However, this technique cannot effectively control the subsequent loops of the welding wire, because the subsequent loops may be jammed in the reduced-size drawing hole, thereby frequently stopping the welding process.
Examples of the drawing device adapted to draw out the welding wire via the outside of the annular member are disclosed in Japanese Patent Laid-open Publication Nos. Hei. 8-40642 and Hei. 9-156827. Similarly to Korean Patent Publication No. 87-1076, Japanese Patent Laid-open Publication No. Hei. 8-40642 discloses an annular member having buffering wings for allowing the welding wire to be freely lowered along the inner surface of the pail pack as the welding wire is consumed. Since the buffering wings are made of a soft material, the welding wire is allowed to be drawn out between the inner surface of the pail pack and the buffering wings. Although this technique can to some extent prevent the subsequent loops of the welding wire from being drawn out by the uppermost loop of the welding wire, other problems may occur. That is, the welding wire may be caught by the buffering wings so that its drawing resistance may be increased. In severe cases, the annular member may be drawn out along with the welding wire.
In order to solve this problem, Japanese Patent Laid-open Publication No. Hei. 9-156827 has proposed an improved buffering wing. However, this technique cannot fully solve the above described problem
In the above-mentioned drawing devices adapted to draw out the welding wire via the outside of the annular member, there is another problem in that a subsequent welding wire loop may frequently be tangled while being moved downward into a space centrally defined in the vertical wound body during the drawing of an uppermost loop of the welding wire.
Other conventional tangling-prevention devices are disclosed in Korean Utility Model Laid-open Publication Nos. 92-16429 and 92-21073, and Korean Utility Model Publication No. 95-483.
Korean Utility Model Laid-open Publication No. 92-16429 discloses a tangling-prevention device including a main annular member adapted to be laid on the top of a tube-shaped wound welding wire body, and an additional annular member with a reduced size to be laid on the main annular member around the central opening of the main annular member, thereby allowing the welding wire to be drawn out between the annular members. However, this tangling-prevention device cannot solve the problem where the subsequent loops of the welding wire are undesirably drawn out. That is, this technique has the same problem as that of Japanese Patent Laid-open Publication No. Hei. 8-40642.
Korean Utility Model Laid-open Publication No. 92-21073 discloses an annular member having engagement steps. However, it is also difficult for this technique to prevent the subsequent loops of the welding wire from tangling.
In order to prevent the subsequent loops of the welding wire from being tangled, Korean Utility Model Publication No. 95-483 discloses a tangling-prevention device including an annular member with a small size to be laid on the top of a tube-shaped wound welding wire body around the central hole of the wound welding wire body, and another annular member provided at its inner surface with buffering wings. In this tangling-prevention device, the welding wire is drawn out between the small-size annular member and the annular member provided with the buffering wings. Although the buffering wings more or less effectively serve to prevent the subsequent loops of the welding wire from being drawn out by the uppermost loop of the welding wire, it is impossible to completely prevent such undesirable drawing of the subsequent welding wire loops. Furthermore, there is a problem in that since there is a space between the buffering wings and the top of the wound welding wire body, the loops of the welding wire may be lifted in the space, so that they may become tangled.